Archives: 2022-01

New machine day: A manual lathe

With the Artisan’s Asylum closed for a relocation, I’ve been without access to a manual lathe for a while. Fortunately, import mini-lathes aren’t that hard to come by!

What’s inside?

What’s inside?

Well, look at that!

Well, look at that!

This is a Sieg C4 derivative from Little Machine Shop, which was about the largest machine I could reasonably move into my basement.

All set up

All set up

It isn’t as rigid as the Colchester at AA was, but it does have power feed and power cross feed which both work just fine. I’ve run into a few minor quality issues, and the spindle runout isn’t great, but it should do for my needs.

Fixed voltage mode for moteus

The most recent moteus firmware release, 2021-12-03, added not one, but two new control modes for less common applications. Previously, mentioned was the “voltage_control_mode” for using gimbal style high resistance motors without changing the sense resistors. In this post, I’ll describe a similarly named, but very different mode “fixed voltage mode” for operating brushless motors as if they were a stepper motor.

For some applications, you don’t care about torque control, or about power consumption at all. Traditionally you would use a stepper motor in those applications, with a correspondingly less expensive stepper motor driver. However, in some cases you may still want to have high rate trajectory control, CAN based telemetry, or have already standardized on moteus controllers for other moving parts of your solution. There are two new options that can be used in such situations: